Dry mouth and cavities: why it matters and what helps

Why a dry mouth leads to cavities

Saliva does more than keep your mouth comfortable. The American Dental Association calls it the mouth’s primary defense against tooth decay.

• It rinses. Saliva washes food bits off your teeth and gums.
• It repairs. Saliva carries calcium and phosphate, minerals that help strengthen teeth against decay.

When saliva runs low, both slow down. That’s why people with a dry mouth that lasts are more likely to get cavities, gum disease, mouth sores and thrush (a yeast infection in the mouth).

What’s probably going on

Dry mouth isn’t a disease on its own. It usually means something else is cutting your saliva. Common causes:

• A medicine. Hundreds of medicines, prescription and over-the-counter, can dry the mouth. They include many for allergies, colds, depression, high blood pressure and bladder control.
• A health condition. Diabetes, Sjögren’s disease (an autoimmune condition that attacks the glands that make moisture), and other autoimmune conditions can all cause it.
• Cancer treatment. Radiation to the head and neck can damage the salivary glands. Chemotherapy can dry the mouth too.
• Not drinking enough, or breathing through your mouth, especially at night.

Getting older isn’t the cause

Older adults get dry mouth more often, so it’s easy to assume it comes with age. The National Institute of Dental and Craniofacial Research and MedlinePlus are clear that aging itself doesn’t cause it. Older adults are simply more likely to take medicines or have conditions that dry the mouth. If your mouth is dry, there’s usually a reason worth finding.

Common signs: a sticky feeling, trouble chewing, swallowing or tasting, cracked lips, a sore throat, and bad breath.

What to do now

These steps can ease the dryness and help protect your teeth.

1. Sip water through the day. Keep a glass or bottle close. Sipping water during meals makes chewing and swallowing easier.
2. Chew sugar-free gum or suck on sugar-free candy. Both get saliva flowing. The National Institute of Dental and Craniofacial Research says some sugarless gums and candies with xylitol may also help prevent cavities.
3. Try a saliva substitute or a rinse made for dry mouth. These add moisture for a while. Look for the ADA Seal of Acceptance on the label.
4. Use a humidifier at night. It can help if you wake up with a parched mouth.
5. Suck on ice chips or sugar-free ice pops. An easy way to add moisture between meals.

What not to do

• Don’t stop or change a prescription on your own. Talk to your doctor first. They may be able to switch the medicine or adjust the dose.
• Skip rinses that contain alcohol. They can dry your mouth further.
• Cut back on caffeine, alcohol and tobacco. All three make dryness worse.
• Go easy on sugary drinks and acidic foods and drinks, especially sipped or snacked on slowly through the day.

When to see a dentist or doctor

See your doctor or dentist if your mouth stays dry, since finding the cause early can keep symptoms from getting worse. Go sooner if you have trouble swallowing, a burning feeling in your mouth, or white patches.

Your dentist can check for new cavities and tell you whether you’d benefit from extra fluoride. Your doctor can look at your medicines and any condition behind the dryness, and may prescribe something that helps your glands make more saliva.

Bring a list of everything you take, including over-the-counter allergy and cold medicines. Those are easy to forget and often part of the problem.

What it costs

Most of the helpful steps cost little: water, sugar-free gum and a dry-mouth rinse from the drugstore. A prescription-strength fluoride gel or rinse, or a saliva-boosting prescription, costs more and depends on your coverage, so ask your dentist and pharmacist for the price before you fill it.

Catching cavities early is the bigger saving. A small filling costs far less than a root canal or a crown. If you don’t have dental insurance, a dental savings plan (a discount membership, not insurance) can lower the price of checkups and fillings at participating dentists.

How to protect your teeth long term

A dry mouth means your teeth need more help than most.

• Brush twice a day with a fluoride toothpaste, using a soft-bristled brush.
• Clean between your teeth once a day with floss or a water flosser.
• Ask your dentist about a prescription-strength fluoride gel or rinse. A stronger fluoride gel or rinse can help prevent cavities.
• See your dentist regularly, so new cavities get caught while they’re small.
• Keep water and sugar-free gum handy so you’re not reaching for sugary drinks or mints.

If your teeth already hurt, see what to do for a toothache right now. A good brush makes the daily routine easier; see the best electric toothbrush.